Toxin-absorbing 'nanosponges' invented at UCSD

The nanosponges soak up pore-forming toxins. This property could make nanosponges a generic therapy for such toxins and venom from snake bites and bee stings.

UCSD nanoengineers have invented a "nanosponge" capable of safely removing a broad class of dangerous toxins from the bloodstream, including toxins produced by MRSA, E. coli, venomous snakes and bees. The nanosponges are made of a biocompatible polymer core wrapped in a natural red blood cell membrane.
— Zhang Research Lab

UCSD nanoengineers have invented a "nanosponge" capable of safely removing a broad class of dangerous toxins from the bloodstream, including toxins produced by MRSA, E. coli, venomous snakes and bees. The nanosponges are made of a biocompatible polymer core wrapped in a natural red blood cell membrane.
/ Zhang Research Lab

The research was published Sunday in Nature Nanotechnology. The study's senior author is Liangfang Zhang, and its first author is Che-Ming J. Hu, both of the Department of NanoEngineering and Moores Cancer Center at UCSD.

Far smaller than a human red blood cell, the nanosponges are coated in red blood cell membranes to avoid provoking the immune system. Their core contains nanoparticles of PLGA, or poly(lactic-co-glycolic acid), which traps the toxins.

Nanosponges absorb toxins and venom

Engineers at the University of California, San Diego have invented a "nanosponge" capable of safely removing a broad class of dangerous toxins from the bloodstream, including toxins produced by MRSA, E. Coli, poisonous snakes and bees. The nanosponges are made of a biocompatible polymer core wrapped in a natural red blood cell membrane.

Working in mice, Zhang's team injected various toxins and tested the mouse survival rate with and without the nanosponges. The nanoparticles lowered the mortality rate from a normally 100 percent lethal dose of alpha-toxin fromStaphylococcus aureus to 56 percent in those given the nanoparticles two minutes after the toxin. In mice given the nanoparticles two minutes before the toxin injection, mortality was reduced to 11 percent.

The toxin-laden nanosponges primarily wound up in the mouse livers, which appeared normal, the study stated.

"The lack of liver tissue damage suggests that the sequestered toxin was safely metabolized, probably through ingestion by hepatic macrophages," the study concluded.

"This is a new way to remove toxins from the bloodstream," Zhang said in a UCSD press release. "Instead of creating specific treatments for individual toxins, we are developing a platform that can neutralize toxins caused by a wide range of pathogens, including MRSA and other antibiotic resistant bacteria," said Zhang, a nanoengineering professor at the UC San Diego Jacobs School of Engineering.

The nanosponges represent a new iteration of the Zhang team's technology; in June of 2011 they demonstrated how drug-carrying particles wrapped in red blood cell membranes could be used to ferry cancer medications. That study was published in the Proceedings of the National Academy of Sciences.